Battlefield games are fully optimized in the drivers. You only need leave the drivers on default settings and in game let the game settings stay on auto. This will likely give you good performance. You can experiment then with the higher presets in game such as all high or ultra. I would imagine that card would be capable of High at 1080p.
If you are seeing drops you may be throttling. Set the power limit slider all the way to the right as far as it will go. This is under Radeon Settings / Gaming / Global Settings / Wattman. This will likely help that issue.
I try to alter this configurations.